Various optical deflectors which deflect incident light have conventionally been studied. Optical deflectors are devices indispensable to, for example, laser scanners used in laser printers or the like. Examples of conventional optical deflectors include polygon scanners, galvanometer scanners, and Micro Electro Mechanical System (MEMS) mirrors. However, since such polygon scanners, galvanometer scanners, MEMS mirrors, or the like include a mobile unit (mechanical mechanism) for moving parts, there is a problem in that a failure easily occurs. For this reason, there is demand for the development of optical deflectors capable of deflecting light without including a mobile unit.
In response to that demand, an optical deflector as disclosed in Patent Literature (PTL) 1 below has been proposed. This optical deflector does not include a mobile unit, and deflects light with use of the fact that the refractive indexes of liquid crystals are modulated by application of voltage. Through this, it is possible to reduce the occurrence of failures and achieve high reliability.
Furthermore, PTL 2 below discloses a liquid crystal display device capable of displaying three dimensional (3D) images using the above optical deflector. This liquid crystal display device deflects, at a predetermined timing, light incident on the optical deflector to be collected on a viewer's right eye viewing a liquid crystal panel. In synchronization with the timing, a right-eye image is displayed on the liquid crystal panel. After the predetermined timing, the light incident on the optical deflector is deflected to be collected on a viewer's left eye. In synchronization with the timing, a left-eye image is displayed on the liquid crystal panel. By alternately switching between a right-eye image and a left-eye image to be displayed on the liquid crystal panel at a predetermined cycle (for example, 8.3 msec: 120 Hz), the viewer perceives the images displayed on the liquid crystal panel as 3D images.